In a turbomolecular pump, a rotor that is formed of turbine blades (rotary blades) rotates at high speeds with respect to fixed-side turbine blades (fixed blades) to exhaust gases. The fixed-side turbine blades and the rotor are arranged within a pump casing that is formed of an inlet flange (see Patent Literature 1).
Generally, when a turbomolecular pump is used, periodical maintenance and overhauling are required. For example, for turbomolecular pumps of the type supported by mechanical bearings, it is indispensable to periodically exchange the mechanical bearings. In turbomolecular pumps with magnetic bearings, mechanical bearing are used as touch-down bearings. In this case, it becomes sometimes necessary to exchange the bearings due to wear after prolonged use of the pumps. Furthermore, when a turbomolecular pump is used in an apparatus that discharges a corrosive gas, the product tends to stick to a gas flow channel in the pump to hinder the operation of the pump, so that it becomes necessary to perform maintenance for removing the product.
In operations of disassembly and assembly of a vacuum pump, no special instruments are needed, so that maintenance of the pump may be entrusted to a dealer other than the manufacturer of the pump and a designated dealer, or the maintenance may be performed by the user himself. However, for not only turbomolecular pumps but also vacuum pumps, severe precisions are required when they are assembled in order to secure vacuum performance and safety. Therefore, maintenance of a vacuum pump which involves disassembly and assembly of the pump is performed by a trained expert operator, that is, by an operator from the manufacturer of the pump or an operator from the designated maintenance dealer.